I ran a search on Google and found this website's tutorial on fixing a Sleep mode problem, but unfortunately none of the steps helped.

My particular problem isn't that something wakes the computer back up (that problem was actually fixed using your methods), but rather that my screen goes black and my computer keeps running.

My previous computer used sleep mode fine, but I just got a new motherboard (Asus P5N-D), case, and processor (Intel Core 2 Quad), so it's no mystery why it doesn't work anymore, I just can't figure out how to restore the option.

I know it isn't a crucial feature of Vista, but I prefer using it over a complete Shut Down, and if you have any suggestions, I would really appreciate it.

Well I did change the Multimedia Setting but that still had no effect. I also checked BIOS and made sure S1 and S3 were active.

I honestly have no idea what else to try.

Well, it works now, LOL. I'm not entirely sure why, but I think that after I changed the Multimedia Setting, and then went into BIOS and changed it from just S1 to both S1 and S3, it solved the problem.

Now the only problem is that when I put it to sleep, my mouse doesn't wake up, LOL. I'll have to check the driver for that.

Ensure that you have the mouse setting, set to wake the computer from sleepmode.

Stop Your Mouse From Waking Up Your Computer

Eusure you have the option checked .

Okay, it's all good now The trick is that when I wake up the computer I have to click the mouse and tap the keyboard to make sure they both wake up too. Can't complain really